Moderna Faces LNP Patent Lawsuit as U.S. Government Immunity Defense Mostly Blocked, Proceeding to Trial

On February 2, the U.S. District Court for the District of Delaware largely refused to uphold Moderna’s asserted immunity for government-supplied COVID-19 vaccine doses in patent-infringement suits brought by Arbutus Biopharma Corp (NASDAQ: ABUS) and Genevant. As a result, the key claims for damages based on vaccine sales will proceed to a jury trial.

Although the court held that only quantities of vaccine directly supplied to U.S. government personnel fall under the exclusive jurisdiction of the Court of Federal Claims pursuant to 28 U.S.C. § 1498, it left to the jury the questions of direct infringement, patent invalidity, and indefiniteness with respect to the core lipid nanoparticle (LNP) patents.

The court also applied prosecution-history estoppel to bar doctrine-of-equivalents arguments for certain molar-ratio LNP patent claims, and it narrowed the scope of expert testimony on issues including government contracts, fraudulent inducement, and indefiniteness, streamlining these theories before trial.

Arbutus Biopharma—now pursuing LNP patent litigation against Moderna and Pfizer-BioNTech—saw its share price plunge after the European Patent Office recently revoked its core patent, then rebound in early February amid renewed optimism over its chronic hepatitis B pipeline. Both the litigation and pipeline developments have been major drivers of the company’s stock performance.

Looking ahead, the U.S. jury trial against Moderna, scheduled for March 9, and key hearings in international proceedings set for the first half of 2026 in Europe and elsewhere are viewed as potential inflection points for Arbutus’s valuation.

Arbutus Biopharma is a Canada-based, Nasdaq-listed clinical-stage biotech company developing Imdusriran, an RNA-interference therapy for chronic hepatitis B, and AB-101, an oral PD-L1 inhibitor, on the foundation of its RNA-interference and lipid-nanoparticle delivery platforms.

As global pharmaceutical companies accelerate the development of mRNA vaccines and RNA therapeutics, litigation and licensing negotiations over the enabling LNP delivery technology patents have emerged as critical value drivers across the biopharma industry.